1. Field of the Invention
The subject invention relates to operation of environments containing photo-addressable ePaper technology.
2. Related Art
Photo addressable ePaper has been developed by the subject assignee, Fuji-Xerox of Japan. The photo-addressable ePaper technology provides a photosensitive medium that, when energized, accepts a light input to generate an image that is maintained on display after the power is removed from the media. For example, if the media is energized and one uses a laser pointer to write on the ePaper, the writing will remain displayed on the ePaper after the power is removed. Similarly, if one projects an image onto the ePaper using, e.g., an LCD projector, when the ePaper is powered, the projected image will remain displayed by the ePaper after the power is removed. There are two different types of ePaper, one that is written to by light from behind, and one that is written to from the front. For further information relating to this technology the reader is directed to: H. Arisawa, et al., “Photoaddressable Electronic Paper Using Cholesteric Liquid Crystal” IS$T NIP17-228 (2001); T. Kakinuma, et al., “Black and White Photoaddressable Electronic Paper using Encapsulated Cholesteric Liquid Crystal and Organic Photoconductor” IDW '02, p. 1345 (2002); H. Kobayashi, et al., “A novel Photoaddressable Electronic Paper Using Organic Photoconductor Utilizing Hydroxy Gallium Phtalocryanine as a Charge Generation Material” Asia Display, p. 1731 (2001); S. Yamamoto, et al., “A Novel Photoaddressable Electronic Paper Utilizing Cholesteric LC Microcapsules and Organic Photoconductor” SID '01 Digest, p. 362 (2001); and U.S. patent application Ser. No. 11/243,603, all of which are incorporated herein in their entirety.
Various technologies have been proposed to provide a “smart room” environment, such as, e.g., for conferences and meetings. Some of that effort has been directed at enabling and controlling display of various images at various locations in the room. One proposal uses an LCD projector, a pan/tilt mirror, and a camera. The mirror is used to deflect the image of the projector to surfaces, walls, or the floor of a room, according to the user's desires. In this manner, a single projector can be used to project images on different locations in the room. However, as can be understood, since the projector is stationary, some surfaces would be tilted with respect to the projector, thereby leading to a distortion in the projected image. Therefore it has been proposed to process the projected image to compensate for the perspective distortion. For further information the reader is directed to F. Kjeldsen, C. Pinhanez, G. Pingali, J. Hartman, T. Levas, and M. Podlaseck, “Interacting with Steerable Projected Displays.” In Proc. of the 5th International Conference on Automatic Face and Gesture Recognition (FG'02). 2002, which is incorporated herein by reference.
In fact, the technology relating to correcting for perspective distortion has been progressed beyond just correction for projection angle. Technologies have been proposed to enable displaying correct images onto arbitrary existing screen surfaces, like wallpapered walls or window curtains. Such projectors can function without an artificial canvas and consequently leave users more freedom in the decision on how and where to project the image. Such projectors combine camera feedback with structured light projection to gain information about the screen surface and the environment. The calibration of such a device enables correction of video signals in real-time. Neither geometry information nor projector or camera parameters need to be known. Instead, the entire calibration and correction (geometry and color) is done on a per-pixel level supported by modern pixel shader hardware. For further information the reader is directed to Bimber, O., Emmerling, A., and Klemmer, T. Embedded Entertainment with Smart Projectors. IEEE Computer, pp. 56-63, January issue 2005, which is incorporated herein by reference.